The folks at Willow Garage have contributed some new tools to OpenCV, known as the "Orient-Brief" or ORB library. They claim it is twice as fast as SIFT, and is patent-free, which could be good news for panorama development.

Ethan Rublee and Vincent Rabaud and Kurt Konolige and Gary Bradski, ORB: an efficient alternative to SIFT or SURF, ICCV 2011 is the paper (coming out this year I guess) but it seems some of the code is already present in the opencv libraries. Just head about it myself recently.